Concrete stair form



Sept. 16, 1952 A. F. POLLMAN 2,610,380

v CONCRETE STAIR FORM Filed April 2, 1948 s Sheets-Sheet 1 WW Adam K Fz Z/man Sept. 16, 1952 A. F. POLLMAN CONCRETE STAIR FORM 3 Sheets-Sheet 2 Filed April 2, 1948 Adam F Pal/222527 Sept. 16, 1952 F. POLLMAN CONCRETE STAIR FORM 3 Sheets-Sheet 3 Filed April 2, 1948 11' IIW MMIHHMH Adam F PBX/man C I I ccomp ny g:- .drawmss;

iprin pl sof th I Patented Sept. 16, 1952 UNITEDSTATES Pram .OFFICE it I a ,610,380 a v oeNcaETE ST-AIB FORM 7 Adam 'Fg Bollnian, Milwaukee, :Wi s.

Application Aprils, mialserial misses r This inventio relates;t cencrete forms and "has more particular reference to asectional or knockdown form especially 1 adapted {for ithenouring of concrete stair units but which is also useful-for the laying of concrete iootingsand sidewalks. g

More pecifically th s nv nt onhas a ts object theprevision eta concrete stair formwhich I comprises a plurality of channel-shapedstructural elements which. may, be-readilyconnected twith oneancther cit-location to provide a series 7 .-.o1fn ubstantia1 y ;.U:.- haned ;frarnes;.sup imp0se one upon. the other .withc rtain of t e, e m n risers-oi ahst irounit, an w th the rema n n le ments defining the si e -of the. t r-m,

With theahoveandother objectsin-view; which will appear as the description proeeeds -this invention resides in the novel construction combination and arran ment; 91:??415 :suhstan: t l y as lnereinafter desorib d -:a .d: more part cu a ly .de- .fi-nedfby the apnen dicle ms; it bein und r- .a uch cha ges in th prec s embpd -ion. {n w be t e; cla m il ust at tw comp ete. a plestot t e hysiceliembo ime :StOOd i. wont 1.0 the ;hereindisolosedmade as come within the scope ;o

- .oi the .i ve tionco ct dsa qord n o t *zbest modesc' iat d ri rth rr i al zca ionof the. princ ple .ereQfian -in w ich.

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Fi ureB- s an .enlarsesirorsp c i e vi woith ,rea o io o the m; horn n Ei urelan .u a n the. m an is lwld ngth -elements of .--t e Qvm a ainst ,sh tineEr -i e to one; an-

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reg tsa fra m ntar e tiona -view take b i $tra n ;t e rel mse eof the f mn rst frae n' ita a rpe seat ras-'11s) tive view of 'a portion of'the form shown in Fig- .um; i. ."Figure 6 tyne of .holdingflmeans form; and v Figure 7 is a perspectiveyiew of the connector or clamping element shown in Figure'6.

Referring no'w'rrioreparticularly to the accompanying drawings in which like numerals indicate like parts, the numeral 5' in Figure 1 "generally designates one type of stair form'which may be is a plan View illustrating a modified tor'the' elements of the produced by thesectional form constructionof this invention. The form is comprised of a number of lengthsof channel-shaped elementsde tachably connected together to provide a front step stair unit having two risers.

This form, as well as others for different types of stair units described later, is constructed from two basic types of elongated channel members .6 and vI which are preferably bent up from sheet metal so as to bought in weight. The channel- 'sha'ped members 6 have their flanges 8v extended atoppositefends as at 9, and the flange'tdfiange distance of theselmembers is slightly greater than tom flanges of one ofthechannelmembers 1 so ends of the channel members 6.

the distance between'th'e flanges'ill on the chan nel-shaped members. i, This allows/one of the channel members 7 to be disposed crosswise of the ends of a pair of channel members 6 with the flanges of the channel member I received between the fiang'eextensions '9 on the adjacent The flange extensions 9 on the ,channel'memhers 6 have vertically aligning holes i2 therein which'may be brought into register with pairs of vertically aligning holes l3 in the. top and botthat insertion of a pin I4 from top 'tobottom through the holes l2 of the flange extensions and th aligning holes .13 in the flanges ill "of the channel members I lock the members .6 and I together. 'ItYis .to be.'understood that the flanges of the channel members Thave a number of sets a .of .yertica11y aligning holes l3, preferably spaced apart equal distances along the. length offlthe members. j

. .By Way .ofexample, the sets of vertically aligning holes IS in the flanges i0 .of the members i may be assumed to belocated 6 apart to enable relatively close adjustment of the spacing be- ..tween. thechannel members 6. Hence, when two back are connected to one ofthe channels 1 in legs'corresnonding to the desired width ofairgnt dimension corresponding to a more or less standard depth of stair tread. In the two-step stair form illustrated in Figure 1 two U-shaped frames are required. The channels 6 defining the legs of each frame are spaced equal distances apart to enable the frames to be superimposed one'upon the other, but the legs of the upper frame are shorter than those of the frame therebeneath by an amount corresponding to the depth of stair tread. Hence, when the outer or free ends of the legs of the two frames are brought into vertical alignment, the webs of the channels 1 are offset to lie in different vertical planes spaced apart a distance corresponding to the depth of stair tread to define the two risers of the form, while the coplanar webs of the superimposed channels 6 define the opposite sides of the form.

The flanges 8 of the channels 6 also have sets of vertically aligning holes l along their length with the spacing between them and the holes l2 corresponding to the spacing of the holes l3. Consequently if the standard depth of stair tread may be assumed to be l2", the spacing of the holes in the flanges oi the channels is one-half the depth of tread. Thus it will be apparent that the lengths of the channels 6 are substantially multiples of the depth of stair tread, or 12".

With this relationship between the side channels 6 of the form shown in Figure l, the pins 14 which secure the channels 6 and l of the upper U-shaped frame together are enabled to pass through the holes 15 in the upper flanges 8 of the members 6 therebeneath so as to not only connect the channels of each individual frame with one another but to connect the frames themselves to one another, as best shown in Figure 2. This is possible since all the holes 12 and I5 of the channels 5 align vertically with one another in the operative position of the-form.

The webs of the superimposed channels 6 are maintained in co-planar relationship partly by means of the pins [4 connecting the legs of each frame with their cross member I, partly by a clamping device generally designated 20, one such clamping device being disposed adjacent to each side of the form near the outer or open ends of the U-shaped frames.

Each of these clamping devices comprises a rod-like standard 2| preferably made of piping having a foot 22 welded or otherwise fixed to one end thereof normal to the aXis of the standard 2 I. The foot 22 is adapted to lie flat upon the ground and it is apertured as at 23 a distance outwardly of the standard to receive a stake 24 so that when the stake is driven int the ground it will anchor the foot 22 flat-wise upon the ground and hold the standard 2| in an upright position.

A plurality of flat clamping plates 25 is provided for each clamping device. These plates have apertures 26 substantially centrally thereof to enable the same to be slid up and down the standard 2! for disposition of the plates at any desired elevation on the standards and normal thereto. Each of these clamping plates has a ends of the webs of the channels 6' are spaced stud 21 fixed thereto at one end of the plate sub-- stantially normal to the plane of the plate and. projecting from opposite sides thereof. These studs are adapted to engage in the apertures 15 of the legs 6 of the U-shapedframes and serve to connect the rear sides of the form with the upright standard 2|. Locking screws 28 threaded; edgewise into the opposite ends of each plate may be brought to bear against the exterior of the upright standard 2| to lock the clamping: plates in operative positions upon the standard. In use with a two step form of the type shown in Figure 1, therefore, three clamping plates are and with the studs 2'! of this plate projecting up wardly into one of the apertures I 5 in said flange, The intermediate clamping plate is disposed to rest flatwise upon the inner surface of the lower flange '8 of the upper side channel with its stud 21 projecting through the aligning holes [5 in the adjacent flanges 0f the side channels. The third clamping plate is engaged flatwise on the top of the uppermost flange of the top side channei with its stud 21 projecting downwardly into one of the holes l5 therein.

Hence, when the clamping plates are locked to the standards 2| in the positions described, by means of the locking screws 28, the outer ends of the side members 6 remote from their cross members 1 are securely held against motion relative to one another, and the webs of the side channels are securely maintained in co-planar relar tionship.

Similar clamping devices 30 are adapted to be employed at the front of the form, and the clamping plates 25 thereon embrace the flanges In of the lowermost riser forming channel 1 to minimize the possibility of shifting of the form when concrete is poured therein and to coopererate with the clamping devices 20 in holding the open ends of the U-"shaped frames against the wall of a building 3| beneath a door opening 32 therein.

If further reinforcement of the form is desired a tiemember 34 may be employed. This tie member is preferably one of the channels 1 as shown and it is disposed across the top of the uppermost U-shaped frame adjacent to the open end thereof with its back or web facing the wall of the building for which the stair unit is intended. Additional pins 14 passing through the vertically aligned holes in the flanges of the tie member to have their lower ends received in the apertures [2 of the side channels'G secure the tie member in place so as to prevent spreading of the sides of the form. Diagonally extending straps 36 having parallel upper and. lower flanges 31 and 38 respectively to overlie the top flange of the tie member and the top flanges of the uppermost side channels 6 may be employed, if desired, to reinforce the connection between the tie member 34 and the topmost U-shaped frame. These diagonal straps 36 are secured to the tie member by the pins l4 passing through suitable apertures in the upper flanges 31 of the straps, and the studs 21 of the topmost clamping plates 25 passing upwardly through suitable apertures v in the lower flanges 38 of the straps.

'When assembled as in Figure 1, theform defines the opposite sidewalls and the risers of the stair unit, as stated'hereinbefore. Since the .infe n"'o niis the nels irom .stair unit which sty1e:of -thestair unit. Hence, by employing the proper lengths of channels; 6,. forms may-beasisembledzto'produce stair units havingonly one "agona-l brace eyeraeso af 'slight distance from the wall anthe buildin by the flange extensions, thin angle-shaped sheet metal retainers 39 a're' "employed to prevent concrete'fro-m leaking outf-ozf these spaces. Each retainerhas one leg d'ispo'se'd over the webs of thechannels -6 a the insidef we form,

"and the other-leg extend-s behind the ends or the channels B-to the exterior of the form and toj' li'e flat' against the wallof the building. "The' "entir'e 'top of the form; however, is" open,

"asijs the treadof the lower step, to enfabltrow- "elling of" concrete poured" into the form. to a rages beneath the level of the underside. ofthe next} higher riser, .this distance'being'a't least twice the thickness oflthe met'al frornwhich-the .channels are formed;

. "One i of the features oi the step form I of this easy adjustability ofthe chanwhich it isassembled. This. adjust ability applies not only to. dimensions of. the itais to define, but'also to-the riser;v or three or more risers.

imposed. U-shaped frames with the channels I .ofiset. relative to one another as bef-ore,,.so. as

'toodefine'. the irisersrforthe three. steps of the unit. Three additionalsuperimposed-channels 1; identical to thechannels I and of equal length however; are connected toatheendsrof the chan- .-n"e1s 6, o'f'.-diiferentillengths; remote fromsi the 'riser'formin'g' members lr The channels land I therefore define the legs of each of thei -superimposed U-sh-aped frames, and the outer or open ends of these frames are adapted to abut the wall 31 of the building beneath the door opening 32 therein as-in theprevious instance but ,With the channel members 1 defining risers perpendicularly to the wall 3|.

Support for the. free-ends of the riser forming channels I is afforded by means of a di- 40. The brace740 is preferably'in an angle iron having an upstandthe form of "mg leg"4'|,f and having a series of substantially tri-angularplates' 42'secured flatwise thereto, one

Hence, theifianges 43 extend over the ends of the treadsadj-a-cent to the building. Pins 45 aligning apertures 46 in-the fian'ges 43 to provide for attachment of the risers to the brace 40, so that each riser is supported from the riser therebeneath.

The brace 40 cooperates with an angle-shaped tie member 41 having a horizontal flange 49 received flatwise upon the flange 43 of the upper most plate 42 at one end, and upon the upper i Y Likewise, a side stair unit. like that illustrated in Figure l maybe. quickly assembled from the channels :Bwand' 1; In this case, the channels are connected together to define-three superrange oi the topmostchannel l at the :oppdsiteend oifthe tie member. The 'ti'e member-:11 in this case maybesecured to the-topmost channel 'I' by one-or the pins l4-passing- 'th-r0ugh a hole in the horizontal flange 49=-of the tie memher and: received in -one oifth'e holes I3'-in the flange of-thechannel 1''; whilethecpposite end of 'the'tief member hasa pair of holes-"therein aligning with the two'hoies'in the flange-43 0f the uppermost-plate 4'2'to receive'a short bolt 52 and" another oneof the mm M; The pin "l'4j'inith'iscase passes through the angle, the mags 43, b'oth' flanges of the" topmost riser I,

andthe top; fiangeof the'channel 1 therebeneath.

"Clamp'ngde 'ces 20 and 30" may againb'e employed topr'eludeshifting of theisides and frontcf the form as previously described.

I The modified form of clamping element shown in Figures- '6 and 7 r is adapted to be substituted for the plate 25*'and,' ,of course, is used for" the same i purpose; namely; to v rigidly connect '.'the channelm'embers with the" upright standards 21. The clamping elementin" this case features easier 'detachability 'and comprises a U-shaped strap" 53of 'a sizetoloosely embrace the stand-- ard 2|. The legs 54 and 55 of the U-shap'ed strap are adapted to lie at oppositesides of the standard 21' and are extended outwardly far enough to wholly receive the standard 2| therebetween.

The'legs have aligning apertures 56 intheir outer tends to receive either arm 51'of' a'lever"58 which confines the'standarcl' in the bottomof the strap when operatively connected with the legs of the strap. The arms of the lever have a round cross section and each arm has a medial portion 59 thereof; offset so as to be eccentric to the axis of its arm. Washers 60', one fixed to eacharm as bywelding; and' adjacent to the juncturebetween' the arms, determine the extent to which the arms ma be inserted 'intothe-aligning holes'56. In additiom these washers locate the eccentric portion 59 of either arm inserted into the holes 56*exact1ymidway between the legs 54' and '55 of the strap, and hence directly opposite the standard between the legs.

" With the strap'in place embracingthestandard, therefore; it is only necessary to insert one "tor: each riseruormingichannel 1; Each of these lpl'ates has 'a'right'angle flange 43 ofv sufiicient length as. to' rest on the top flange of one of the risers and to bear against the underside of the lower flange of the next higher riser. 1 l

. are. inserted into; the apertures. 13 in-the' flanges nearthe outer ends oi. the risers T and through of the arms of the lever into the holes in" the outer endsof the legs of'the'strap, andwiththe concave side of" the ecc'entric SQ' on said arm 'facing'" the standard. 'Then', upon rotation of the lever by means of the handle affordedby the other arm, the eccentric portion of the arm is brought to bear against the standard with a force which increases to maximum 'at1'80' rotation ofthe lever from its inserting and withdrawing position. The force with which the lever arm'is thus engaged with the standard" is more than adequate to hold the U-shap'ed' strap in any. d'esired'position along the-length of the standard.

The, U,shaped strap is connectible with the channels of the form by means of studs. 62 welded or otherwisesecured-to a-bar 63 which in turn is welded edgewise to the side of one of the legsof the strap.- The studs project from the opposite faces of the bar, and their spacing corresponds to the spacing of the holes in the flanges of the channels 6, 1 and 1' so that the engagement of both studs in adjacent holes in the flanges of the channels is required to anchor the channels to the standard 2|.

The clamping elements shown in Figures 6 and '7 are especially useful for joining the longitudinally telescoped ends of channels 15 and! .telescOped together and arranged in opposite back to back relationship for the provision of concrete footing or sidewalk forms. Y

As shown in Figure 4, the standards 2] may be employed without the feet 22, and in this event the standards themselves are driven into the ground adjacent to the form tolprovide the necessary rigidity for the standards.

It will also be appreciated that, while only two types of stair units have been disclosed'in Figures 1 and 4, forms for other types of stair units having opposing sets of steps, as well'as steps on three sides thereof, may be readily assembled from the channelmembers 6 and I.

From the'foregoing description taken in connection with the accompanying drawings, it will be apparent to those skilled in the art that this invention provides an exceptionally simple sectional form construction for concrete stair units which features adjustability to enable considerable variation in dimensions of the stair unit, as well as versatility in enabling assembly of forms for a number of different types of stair units. 7

What -I claimed as my invention is:

l. A concrete form characterized by: elongated "channel -shaped members each having parallel flanges spaced apart a common distance and ,provided with equispaced aligning sets of holes; other elongated channel-shaped members each having parallel flanges spaced apart a distance greater than the flanges of the first designated channel members an amount substantially equal to twice the flange thickness; apertured flange portions extended lengthwise from one end of each flange of each of said other channel members and adapted to engage over and under the flanges of said first designated channel members with the apertures of the flange extensions in register with sets of vertically aligning holes in the flanges of said first designated channel members; and means engageable in said registering apertures for locking the channel members together.

2. A sectional form into which concrete is adapted to be poured to produce a stairunit comprising: a pair of superimposed U-shaped frames having elongated channel-shaped legs and backs with the flanges thereof turned outwardly of the form, the webs of the channel-shaped backs being wider than the webs of the channel-shaped legs byan amount substantiallyequal to twice the thickness 1 of the flanges of the..channelshaped backs, the back and. one leg of the upper frame overlying the back. and corresponding leg of the frame therebeneath, andjthe back of the upper. frame being shorter than, the back fof the frame therebenath to dispose the remaininglegs of the frames in offset relationship so that'said oifset legs provide stair risers for the form, while the first-named legs and the backsof the frames provide upright angularly disposed sides for the form; and detachable connections between the backs of d the frames and their respective legs and between the frames for holding the same against shifting relative to one another, said detachable connections comprising; flange extensions on the opposite ends of the channel shapedbacksoverlying and underlying the flanges of the legs'so that the top of "the .leg which defines the lowest stair riser is on a lower elevation than the bottom of the leg which defines the next higher riser, and removable pins passing through aligned'holes in the flange extensions and flanges. ,7

3.; The form' set forth in claim 2 further characterized by' 'the provision of a diagonal member connected with said'oifset legs adjacent to their outerends for holding the same in saidoffse't relationship; f

'4. The form of c1aim'3 further characterized by the provision of a tie member connected acrossth'e' open end of the top U-shaped frame and cooperating with said diagonal member to preclude shifting of the frame parts relative to one another. f c Q 5. 'A sectional form for a poured concrete stair unit characterized by: a pair ofspaced apart side forming channel members arranged backto-back; a second pair of spaced apart side form'- ing channel members shorter than the first pair by the depthof a stair tread, said second pair of channel members also being arranged backto-back and being superimposed'upon the first pair; a channel shaped riser extending crosswise of each pair of said back-to-back channel members directly across one end thereof with the flanges of the risers turned outwardly o the form, the webs of said risers being narrower than the webs of the channelmembers by twice the thickness of the flanges of said channel members; and readily detachable connections between the superimposed side forming I channel members and the risers holding thev same'in proper step forming relation, said connections comprising extensions of the flanges on the ends of the side forming channel. members adjacent to the risers overlying and underlying the flanges on the risers so that the top of each riser-is a definite distance below the level of the underside of the next higher riser, and pins passing through aligned holes in ,said flange extensions and the flanges of the-risers.

ADAlVl F. P'OLLMAN. REFERENCES CITED The following references are of record in the file of this patent: i V

UNITED sr-A'rEs PATENTS V V N a me v Date ;5 54,857 'Bond et al. Feb. 18, 1896 7 828,031 Kemper Aug. 7, 1906 995,630 f Naugle June 20, 1911 1,012,735 Smock Dec. 26, 1911 11,538,604 Thrasher et a1. May 19, 1925 1,672,760 'Heltzel June 5, 1928 1,803,719 Miller: May 5, 1931 2,237,997 L Moccia; 1' Apr. 8, 1941 2,264,082 Kintz Nov. 25, 1941 I O THER REEERENCES I Adjustable :All-Steel Form for Concrete Steps, Engineering :News Record, (vol. p 808- 810, pages -126, Dec. 12, 1946), e 

